The invention relates to an apparatus for folding folded products with sealing flaps and with or without mating flaps, especially such as packaging bags including envelopes.
For many years, apparatus of the type of interest here have been on the market and are used to a great extent in the production of packaging bags including envelopes. In order to fold over the mating flaps and the sealing flaps, the almost completed packaging bags or envelopes are held against a stop and then, during the following opposing movement, are folded over with the aid of suction elements on a mating flap roll or on a sealing flap roll and then transported onward and, for example, deposited with the aid of a paddle wheel.
Furthermore, DE 22 18 085 C2 discloses an apparatus for folding the sealing and mating flaps on envelopes with self-adhesive glue, the flaps being lifted and turned over with the aid of two suction rolls. In addition, a recess is arranged in one suction roll and, adjacent thereto, a suction bar.
The apparatus disclosed by DE 22 18 085 C2 operates considerably more slowly than the folding apparatus on the market and, for this reason, is technically obsolete. Added to this is the fact that the folding apparatus on the market is also suitable for the production of other envelopes which do not have any self-adhesive glue on the sealing flap and instead, have a contact adhesive which becomes effective when moistened, and also no mating flap. For this purpose, however, a suction roll, that is to say the suction roll with the suction element for the mating flap, together with its drive, has to be pivoted completely out of the movement path of the folding product to be completed or the envelope to be completed. The technical outlay associated with this is considerable and is to be avoided.
It is an object of the invention to avoid the disadvantages of the prior art. In order to achieve this object, the invention proposes that the radius of the mating flap roll, which bears the suction element that turns the mating flaps over, be reduced over a portion of the roll""s circumference, and that the mating flap roll can be locked, in such a way that a folding product can be moved past it to the stationary stop even without contact or virtually without contact.
With the aid of the aforementioned features it is possible, on one and the same apparatus, to produce packaging bags including envelopes with a sealing flap and mating flap on the one hand, or only with a sealing flap on the other hand, whereby it is not necessary to convert or reconfigure the apparatus, and only the mating flap roll needs to be stopped in a defined position. The defined position is given when the packaging bag or the envelope can move from the sealing flap roll in the direction of the stationary stop without in so doing significantly touching the mating flap roll. It is therefore possible for various types of envelopes to be completed without difficulty on one and the same machine. The features provided for this purpose according to the invention are not only technically less complicated and also cheaper in terms of production, but they can also be handled more quickly and more simply than the comparable measures according to the prior art.
In addition, the invention provides for at least one suction element to be arranged on the mating flap roll and to project beyond a cylindrical circumference of the mating flap roll. The suction element is no longer integrated in the circumference of the mating flap rollxe2x80x94as in the prior partxe2x80x94and ends at least partly flush with the latter, instead it is elevated like a driver or finger beyond the circumference of the mating flap roll. Nevertheless, during the production of envelopes with self-adhesive glue on both flaps, the suction element is able to grip the mating flap to be turned over by it both securely and reliably, in particular since the envelope is at the same time still stabilized with the aid of the sealing flap roll. In this case, the suction element of the sealing flap roll only releases the sealing flap when the suction element of the mating flap roll has folded over the mating flap completely or virtually completely.